Strategy-proof coalition formation

We analyze coalition formation problems in which a group of agents is partitioned into coalitions and agents' preferences only depend on the coalition they belong to. We study rules that associate to each profile of agents' preferences a partition of the society. We focus on strategyproof rules on restricted domains of preferences, as the domains of additively representable or separable preferences. In such domains, only single-lapping rules satisfy strategy-proofness, individual rationality, non-bossiness, and flexibility. Single-lapping rules are characterized by severe restrictions on the set of feasible coalitions. These restrictions are consistent with hierarchical organizations and imply that single-lapping rules always select core-stable partitions. Thus, our results highlight the relation between the non-cooperative concept of strategy-proofness and the cooperative concept of core-stability. We analyze the implications of our results for matching problem

Strategy-Proof Coalition Formation

We analyze coalition formation problems in which a group of agents is partitioned into coalitions and agents' preferences only depend on the coalition they belong to. We study rules that associate to each profile of agents' preferences a partition of the society. We focus on strategy-proof rules on restricted domains of preferences, as the domains of additively representable or separable preferences. In such domains, the only strategy-proof and individually rational rules that satisfy either Pareto efficiency or non-bossiness and flexibility are single-lapping rules. Single-lapping rules are characterized by severe restrictions on the set of feasible coalitions that are consisitent with hierarchical organizations. These restrictions are necessary and sufficient for the existence of a unique core-stable partition. This fact implies that single-lapping rules always select the associated unique core-stable partition. Thus, our results highlight the relation between the non-cooperative concept of strategy-proofness and the cooperative concept of uniqueness of core-stable partitions.Coalition Formation; Strategy-Proofness; Single-Lapping Property; Core-Stability; Matching Problems.

Strategy-proof coalition formation.

We analyze coalition formation problems in which a group of agents is partitioned into coalitions and agents' preferences only depend on the coalition they belong to. We study rules that associate to each profile of agents' preferences a partition of the society. We focus on strategyproof rules on restricted domains of preferences, as the domains of additively representable or separable preferences. In such domains, only single-lapping rules satisfy strategy-proofness, individual rationality, non-bossiness, and flexibility. Single-lapping rules are characterized by severe restrictions on the set of feasible coalitions. These restrictions are consistent with hierarchical organizations and imply that single-lapping rules always select core-stable partitions. Thus, our results highlight the relation between the non-cooperative concept of strategy-proofness and the cooperative concept of core-stability. We analyze the implications of our results for matching problems

Feasibility Constraints and Protective Behavior in Efficient Kidney Exchange

We propose a model of Kidney-Exchange that incorporates the main European institutional features. We assume that patients do not consider all compatible kidneys homogeneous and patients are endowed with reservation values over the minimal quality of the kidney they may receive. Under feasibility constraints, patients' truthful revelation of reservation values is incompatible with constrained efficiency. In the light of this result, we introduce an alternative behavioral assumption on patients' incentives. Patients choose their revelation strategies as to “protect” themselves from bad outcomes and use a lexicographic refinement of maximin strategies. In this environment, if exchanges are pairwise, then priority rules or rules that maximize a fixed ordering provide incentives for the patients to report their true reservation values. The positive result vanishes if larger exchanges are admitted.Kidney, Matching, Protective Behavior

Planning and Scheduling of Business Processes in Run-Time: A Repair Planning Example

Over the last decade, the efficient and flexible management of business processes has become one of the most critical success aspects. Furthermore, there exists a growing interest in the application of Artificial Intelligence Planning and Scheduling techniques to automate the production and execution of models of organization. However, from our point of view, several connections between both disciplines remains to be exploited. The current work presents a proposal for modelling and enacting business processes that involve the selection and order of the activities to be executed (planning), besides the resource allocation (scheduling), considering the optimization of several functions and the reach of some objectives. The main novelty is that all decisions (even the activities selection) are taken in run-time considering the actual parameters of the execution, so the business process is managed in an efficient and flexible way. As an example, a complex and representative problem, the repair planning problem, is managed through the proposed approach.Ministerio de Ciencia e Innovación TIN2009-13714Junta de Andalucía P08-TIC-0409

Arqueología del Futuro. La movilidad como opción de futuro. Viviendas móviles, transportables, desmontables

A través de la Historia aparecen muchas y variadas manifestaciones de cambio necesarias para afrontar el futuro 2 de la arquitectura, o lo que es lo mismo, de las ciudades. Estas manifestaciones, alternativas, teorías, proyectos, a menudo denostados por la crítica o dejados de lado por lasTeorías Históricas de carácter generalista 3 , destacan por la generación de nuevas visiones, fuera de los marcos convencionales (dentro de la modernidad) de la arquitectura contemporánea. Su carácter prospectivo dibuja un gran elenco de posibles futuros que deben ser estudiados, analizados, catalogados, desde una perspectiva actual (ese futuro imaginado desde el pasado) que permita evaluar los grados de vigencia de los mismos a través de una Arqueología del Futur

A CSP model for simple non-reversible and parallel repair plans

Thiswork presents a constraint satisfaction problem (CSP) model for the planning and scheduling of disassembly and assembly tasks when repairing or substituting faulty parts. The problem involves not only the ordering of assembly and disassembly tasks, but also the selection of them from a set of alternatives. The goal of the plan is the minimization of the total repairing time, and the model considers, apart from the durations and resources used for the assembly and disassembly tasks, the necessary delays due to the change of configuration in the machines, and to the transportation of intermediate subassemblies between different machines. The problem considers that sub-assemblies that do not contain the faulty part are nor further disassembled, but allows non-reversible and parallel repair plans. The set of all feasible repair plans are represented by an extended And/Or graph. This extended representation embodies all of the constraints of the problem, such as temporal and resource constraints and those related to the selection of tasks for obtaining a correct plan.Ministerio de Educación y Ciencia DIP2006-15476-C02-0

Supporting the Optimized Execution of Business Processes through Recommendations

In order to be able to flexibly adjust a company’s business processes (BPs) there is an increasing interest in flexible Process-Aware Information Systems (PAISs). This increasing flexibility, however, typically implies decreased user guidance by the PAIS and thus poses additional challenges to its users. This work proposes a recommendation system which assists users during process execution to optimize performance goals of the processes. The recommendation system is based on a constraint-based approach for planning and scheduling the BP activities and considers both the control-flow and the resource perspective.Ministerio de Ciencia e Innovación TIN2009-1371

A Constraint-based Model for Multi-objective Repair Planning

This work presents a constraint based model for the planning and scheduling of disconnection and connection tasks when repairing faulty components in a system. Since multi-mode operations are considered, the problem involves the ordering and the selection of the tasks and modes from a set of alternatives, using the shared resources efficiently. Additionally, delays due to change of configurations and transportation are considered. The goal is the minimization of two objective functions: makespan and cost. The set of all feasible plans are represented by an extended And/Or graph, that embodies all of the constraints of the problem, allowing non reversible and parallel plans. A simple branch-and-bound algorithm has been used for testing the model with different combinations of the functions to minimize using the weighted-sum approach.Ministerio de Educación y Ciencia DIP2006-15476-C02-0

OptBPPlanner: Automatic Generation of Optimized Business Process Enactment Plans

Unlike imperative models, the specifi cation of business process (BP) properties in a declarative way allows the user to specify what has to be done instead of having to specify how it has to be done, thereby facilitating the human work involved, avoiding failures, and obtaining a better optimization. Frequently, there are several enactment plans related to a specifi c declarative model, each one presenting specifi c values for different objective functions, e.g., overall completion time. As a major contribution of this work, we propose a method for the automatic generation of optimized BP enactment plans from declarative specifi cations. The proposed method is based on a constraint-based approach for planning and scheduling the BP activities. These optimized plans can then be used for different purposes like simulation, time prediction, recommendations, and generation of optimized BP models. Moreover, a tool-supported method, called OptBPPlanner, has been implemented to demonstrate the feasibility of our approach. Furthermore, the proposed method is validated through a range of test models of varying complexity.Ministerio de Ciencia e Innovación TIN2009-1371